3.2. Morphological observations of di erent CCTO samples
The morphological di erences between the particles obtained by above mentioned two methods are illustrated in SEM photomicrographs in Fig. 3. The CCTO/T ceramics have the largest particle sizes (ranging between 1.5 and 2.5 µm) of any of the studied samples. Sinters are also visible in the material. Smaller crystals are present along the edges of the particles that are caused probably by a liquid phase of CuO that forms under high temperature conditions and recrystallizes when the sample is cooled, as evidenced Fang and Mei [36].